Today/tomorrow’s mid-latitude cyclone on the Great Plains and Midwest will be a powerful one and one which will provide something for everyone. Blizzards, wind, severe storms, flash flooding, fire…pick your poison, Nature will provide.
In places like Minneapolis and much of Nebraska, this storm threatens to be a historic late-season April heavy snow or blizzard event. In the southern Midwest and South, it threatens heavy rain, flooding and a tornado outbreak. On the southern Plains, strong winds and arid conditions, could further yesterday’s extreme fire behavior. Stay safe out there folks!
A reminder, I will be interviewed on the internet-based program Environmental Coffeehouse at 9 pm EDT/6 pm PDT tonight! A livestream will be available on their public FB page (so you should be able to see it regardless of whether you have a FB page or not). I will discuss abrupt climate change and increasing extreme weather events and how current events (ocean heatwaves, changing jet stream, etc) connect to our rapidly changing climate.
If you’re wondering why all this is happening…VERY amplified…or in other words…very wavy jet stream pattern bringing extremely cold air (by April standards) down from from Canada to meet with up with extreme warm air (again by April standards) up from the south. Temps in 20s and 30s to the north with a high of 101 in Western Oklahoma yesterday to the south. Right now Lincoln, NE (where I am) is hitting 80 degrees for the first time this year. Tomorrow, Lincoln will peak in the mid-30s with falling temperatures!
The front end of this trough caused the development of the surface cyclone over Nebraska, intensifying deep moisture movement from the Gulf of Mexico (which, by the way, as a moisture source region, is running well above normal to start the year) and as and providing the deep vertical wind shear (rapidly increasing wind speeds with height) need to generate sustained severe thunderstorms. A recipe for a multi-threat mid-latitude frontal system. And it will not stop anytime soon. Saturday night, the threat will spread eastward, where a significant ice storm event may be possible for portions of upstate New York. In fact, Saturday afternoon, there may be much of Pennsylvania in the 70s while much of Upstate New York may be in the 20s! Incredible temperature contrasts for such a relatively higher latitude location.
—Meteorologist Nick Humphrey
Friday Night, I’ll be interviewed on the internet live show Environmental Coffee House by host Sandy Schoelles. The show (started by a concerned non-scientist interested in the environment, science and technology) discusses a variety of environmental and climate issues. I’ll be brought on to talk about increasing extreme weather events, climate change and abrupt tipping points, and environmental destruction, including the 6th mass extinction. The show will be live streamed on Facebook and has thousands of followers. Give it a watch, it’ll be a serious discussion (maybe 30-40 mins), but should be fun.
Below are some articles which may relate to what we discuss in the interview. Almost all are VERY recent articles! (First three articles are technical peer-review papers, remainder are recent news articles for non-scientist consumption).
More science-y but still understandable for non-scientists. Presentation by Dr. Peter Carter on major threat to food production in the United States bread basket by extreme heat: YouTube Video (2017)
Nebraska is in the ice box still…but big storms, including tornadoes and significant straight line wind damage possible in parts of Indiana and Kentucky today.
Warm, moist air, and lots of vertical wind shear. Good set up for some nasty severe weather.
There is a lot of speed shear, but not as much change in direction with height, which favors lines of storms. So the threat for damaging winds is quite significant, hence the “moderate risk” (4 out of 5 on the overall scale by the Storm Prediction Center) for a 45% chance of damaging wind reports within 25 miles of a point within the given region, and a 10% or higher chance of winds over 74 mph (hurricane-force). However, a significant tornado risk also exists for storms which do isolated themselves earlier this afternoon. So remain vigilant if you are in these areas and tell anyone you know to remain ready to take cover this afternoon and evening!
My part of Nebraska?
Unseasonably cold. Just straight up…cold. Starting off spring as if it were February with temperatures 25-30 degrees F below normal for highs and 15-20 degrees below normal for lows. Will have some recovery later this week, but near normal conditions (+-5 degrees F) don’t appear consistently likely until early next week. Thursday may give us a one day break with mid-50s (normal is around 60 F). So far our warmest day this year was March 3rd (73 F). The Great Plains have been part of the very wild weather pattern impacting much of the mid to upper mid-latitudes this year thanks to a highly oscillating jet stream with periods of very cold and very warm conditions relative to local norms. Much of Europe has gone through the same with very cold Arctic air mass spells, while the parts of the East Coast had record heat in February, followed by multiple cold and heavy snow periods from damaging nor’easters. All while the Arctic roasted in heat waves in this winter (relative to their norms) has significant heat and moisture moved northward, hitting sea ice hard. Here in my locality, we’ve had the roller-coaster ride of going from a a high of 4 to a high of 56 in ten days (January), a high of 22 to a high of 65 in seven days (February; and actually the high was 58 two days before that high of 22…ha!) to our mid-May days in early March (low-70s). Now after the last 5 days of March in the more seasonable 50s to low-60s, we’re spending the first three days of April barely above freezing. Winter was wild and Spring is starting off confusing weather even by spring standards. At least it’s not record breaking cold, it is unusually cold regardless though. Looking forward to the actual warmth of spring again.
One thing I notice with human uncertainty and understanding of climate change is our memories are quite short. We don’t always remember how things have changed in the places we have lived in our relatively short lifetimes on this Earth.
Sometimes perspectives from the past help us out.
You might remember in my previous post I discussed a rather random exchange I witnessed between a Mom and adult daughter in a coffee shop where I live, effectively about how the winter climate has changed in Nebraska over the decades. The daughter says “these wild swings (in temperature) are normal”. And the Mom basically says “Not so fast!”…”I remember when it used to be more consistently cold and snowy all winter long”. Basically back in the day there wouldn’t be low 70s in February.
So what’s “normal?”
It’s a strange concept, if you think about it, but an important one. As a meteorologist (who aren’t climatologists), we use “normal” as a moving target. The previous 30 calendar years as the standard for “normal”. So it’s 2018, so we compare what’s happening today or this week or this month thus far to the previous average for the 1981-2010 time period. During the previous decade, we used 1971-2000, the previous decade before that, 1961-1990, etc. But when your “normal” is shifting with time, it’s under the assumption that the climate of your region is relatively stable with natural variability. But it is not any longer. Anthropogenic climate change being produced by industrial civilization is strongly dominating our planet in timescales of years to decades, which means, moving the “target” to some degree actually masks just show significant global warming is changing the climate of a given area (and of course the planet as a whole).
Without data or communication across generations, the current pace climate change (which is still nearly 170 times faster the past 50 years than the previous 10,000 years) can still go unnoticed by the current living generations of people who haven’t noticed or experienced the weather of the “past climate”. Here are some rather stark examples-
I decided to take a look at climate data from the National Climate Data Center for the city of San Diego. I gathered temperature data from San Diego International Airport for the period 1998-2017 and from the San Diego Weather Bureau (the ancestor to the modern National Weather Service) for the period 1890-1909. The most significant symptom of climate change is the shift of the weather to more extreme conditions. Extremes which never occurred previously, but also known extremes which become much higher in occurrence. In this case I looked at the occurrence of low temperatures at or below 41 degrees F (5 C) and the occurrence of high temperatures at or above 86 degrees F (30 C). The results were…stunning.
High temperatures at/above 86 F: 62 (Highest temperature in period: 100 in 1909).
Low temperatures at/below 41 F: 206
High temperatures at/above 86 F: 158 (highest temperature in period: 101 in 2012/2016).
Low temperatures at/below 41 F: 28
So what’s normal? If you account for the fact that climate change has been underway since the late 19th century (and before that), occurrences of high temperatures at/above 86 F are running 96 days above normal, while occurrences of low temperatures at/below 41 F are running 178 days below normal. If you were born in the 80s or 90s in San Diego might not even realize your city used to be a lot cooler place. And I do mean A LOT cooler, even if you have actually notice it has warmed more abruptly since you were younger.
I did this same “instant study” for my home city of Seattle some months ago. I don’t have the numbers on me any longer, but it was for shorter time frames (1896-1905) and (2008-2017) looking at high temperatures at or above 90 degrees F. Less than a dozen 90 degree days during the early era vs. nearly *60* in the most recent era, as well as the all-time record high for Seattle of 103 in 2009. Nearly 60 days at or above 90 degrees in just one decade! I don’t remember the exact values for the low temperatures (at or below 32) but there was a notable drop in the number of below freezing temperatures compared to the past. But even going back to my childhood…born in 1984 and a “child of the 90s”. I remember significantly cool, wet periods in the summers, 90 degree temperatures being possible, but rare. When Seattle had its first 100 degree temperature on record in 1994, it was my first experience with triple digit heat in my life and it was absolutely awful. The 2009 heat wave (my last full summer living in the city) was equally roasting with no air conditioning in my parents apartment. In a climate where such heat is rare, many buildings don’t have air conditioning. You use fans and block your (open) windows from the relentless sun with whatever you can. Builders didn’t plan for the summer heat of climate change. And now I look at the 2010s and see more roasting hot summers in the Northwest, raging fires in Western Canada, ashfall in Seattle from those fires. Changing times for my home region.
Continuing beyond the data, stories from the past can give us a glimpse into previous climate regimes. Yesterday, I was discussing with my friend and Florida author Vanessa Blakeslee about how climate has changed via a humanities perspective. She discussed with me the mid-1930s novel “Cross Creek” by author Marjorie Kinnan Rawlings. She lived in rural north-central Florida and in the novel, the timing of the summer rains are mentioned and “long, cool winters” are reminisced…temperature and precipitation patterns which Vanessa told me are typically very much different today compared to more than 80 years ago.
So what’s normal? What allows humanity the resources (fertile soil, water availability) to sustain agriculture and feed a population, from which towns and cities and economies can grow and develop. The past 10,000 years of a Holocene epoch has witnessed climate stability which has allowed humanity to know when the rains will come, when the rivers will flood, when the dry seasons happen, when to expect the snows, etc. Variability, yes, the occasional extreme sure. But you KNEW the pattern.
But now we’re leaving that behind. There’s no “new normal” in the “Anthropocene”, there’s only a continuous and accelerating shift to more extreme conditions until climate change stops. It only stops when the planet is back in energy balance given the amount of energy its greenhouse gasses are forcing it to retain. And given what humanity has already done to the atmosphere and the continuous acceleration of changes in the climate system, our planet still has much more to go through to get to that actual “new normal”. But it will be likely full of catastrophic impacts for humanity and already so for many species.
Quite the day out in weather world, although you wouldn’t know it from looking outside here in the land of the corn. Beautiful day, although still waiting for the leaves to make an appearance. Soon enough, but the sun shines bright overhead. Calming and peaceful for a walk later.
After a winter which was tumultuous with big temperature swings (sometimes 50 degrees F within days), it’s nice to have a little stability for some days. Looking near or mildly above normal temperatures the next several days with periods of rain showers. Our winter in this region was less than 0.5 C below normal relative to 1981-2010, but running 0.5-1 C above normal relative to 1881-1910 when factoring the effect of climate change. And temperatures from anthropogenic climate change began rising globally after the mid-1700s, so late-19th century values are still conservative on the changes which have occurred here. People around here were complaining about how cold it was this winter. It could’ve been a lot worse as we had a few 60 and 70 degree temperatures in February mixed with the 10s and 20s for highs in January and February! Just wild.
Actually reminds me of a story in the coffee shop of a mother and adult daughter discussing this past winter. The daughter saying how “normal” it was to have these huge swings in temperature and crazy weather (snow then short-sleeve weather). Mother saying “Well I remember when I was young, it would be more consistently cold with a lot more snow, not like now”. What’s normal has changed with time in a lot of world, but you wouldn’t know it unless the different generations notice and chit chat about it.
Our chances of snow appear to be over. Never say never, as the East Coast seems to be getting blasted by these cold storms, but when you start seeing these consistent mild conditions finally, it’s usually a sign of the seasonal transition…finally.
I do have some concern over this Spring’s tornado season I must say. La Nina periods in the El Nino Southern Oscillation tend to be known for quite intense tornado outbreaks. Trying to get a science paper reading in about it this week if I can. The Gulf of Mexico waters are running above normal for moisture, the South has been quite warm overall with record warm days and months this winter. And jet stream dynamics continue to be favorable for bringing periodic shear profiles for significant severe weather. The atmosphere put on quite a show this weekend in the Deep South where it is climatologically favorable for tornado activity. Reminds me to prep an emergency kit. We do have a weather radio, but with things like tornadoes and urban flooding, you never know when you will need a little more to get through a few days of darkness and no refrigeration.
While, it’s quiet here, the West and East Coasts are being battered by major winter storms to start Spring. Very strong upper-level trough over the eastern third of the country and another over the Eastern Pacific means the 4th nor’easter of the month in the East and huge atmospheric river event in Southern California. Heavy snow or flooding/mudslides?
Good mid-week to all and stay safe in these stormy areas!
–Meteorologist Nick Humphrey
The US will be a land of extremes as a high amplitude jet stream…the story of this winter continues to impact the US as very abnormally cold temperatures impact the Central US and (later) the Great Lakes region, with very abnormal heat spreading northward into the Eastern third of the country mid-week. Sunday, much of the Great Plains were experiencing temperatures 20-25 degrees F above normal (~10-12 degrees C). As the week progresses, the jet stream amplitude over North America will intensify and bring highs of 30 degrees F (15+ C) or greater above normal mid-week to the Ohio and Tennessee Valleys into the mid-Atlantic and New England states. This means mid-Spring highs on the East Coast and a resumption of well below freezing temps over the Central and Northern Plains.
In addition to the abnormal temperatures, another major story will be potentially heavy rainfall across a wide swath of the Midwest and Deep South ahead of the accompanying cold front which will push eastward mid-week. Abundant moisture from the Gulf of Mexico will aid in the generation of rainfall, some of which will help short term drought conditions, but could also produce flash flooding.
The Arctic Ocean has been experiencing an extraordinarily warm winter with consistent high heat to the region (relative to regional norms). As a result, sea ice has been suffering severely as the combination of high amplitude high pressure ridging and ocean cyclones push heat, wave action and wind into the sea ice sheet, along with very abnormal sea surface temperature right up against the sea ice (9-18 degrees F/5-10 degrees C above normal). Sea ice extent is currently running at the lowest on record in the history of human civilization, rapid melting already in progress in the northern Bering Sea, and 2017 annual sea ice volume was the lowest on record. The current max extent this season occurred on February 6th. The current earliest maximum peak extent is February 25th in 2015. The current record year for record minimum peak extent is 2017…2018 is currently beating that record and has the 2nd lowest year-to-date volume as well.
The sea ice is showing some signs of refreezing after its early February peak. However, more extreme heat is to come as more storms from both the Bering Sea and the North Atlantic advance heat and moisture into the Arctic Ocean this week. One storm will move over far Eastern Siberia and into the Chukchi Sea on Tuesday. Wednesday, another, stronger storm will approach Greenland, moving over the Canadian Archipelago Thursday, slowly shifting toward the Beaufort Sea Friday.
Note the last two sea level pressure images for 2/23 and 2/24. Not only the strength of the cyclone (in blue) but the tightly packed lines of equal pressure (isobars) between the low pressure system and the strong high pressure system over the Barents Sea, north of Scandinavia. These tightly packed isobars represent a very strong pressure gradient which will result in very strong southerly wind gusts (near hurricane-force) and intense wave action striking the sea ice sheet of the Arctic Ocean mid to late week. This in combination with the very warm, moist air moving into the region will make for a “blow torch” of heat from the Atlantic, eroding the cold conditions of the Arctic, stunting the freeze season further. This will likely lead to further ceasing or recession of sea ice as well.
I’ve been tracking the Arctic all season and there has been a shocking level of persistent warmth in the region with 2-3 degrees C above normal temps (for the region) being quite common many more extreme day higher than that. The Arctic Ocean basin may experience, as a region, anomalous temperatures of an incredible 6-8 degrees C above normal Tuesday-Saturday. This is relative to the 1981-2010 average. However, as climate change is abruptly warming the Arctic region, leading to rapid sea ice loss compared to the past, relative to the late 19th and mid 18th centuries (in the early era of human generated climate change), the anomalies are likely 0.7 or 1 degree C higher than that, respectively.
The implications for the collapse of sea ice are quite serious. The sea ice sheet regulates the jet stream by making the Arctic region permanently cold across a wide area. As long it it remains permanent with only modest seasonal melt, it can behave much like a continental ice sheet would behave on the atmosphere (like in Antarctica). The jet stream exists because the Arctic atmosphere is cold throughout the vertical column. The strong temperature gradient with the mid-latitudes is what makes it exist. But with abrupt warming of the Arctic caused by the collapsing ice sheet (which feeds back on accelerating such a collapse), this weakens the jet stream and has been causing it to become wavier with increasingly more extreme and frequent high amplitude patterns (which feedback and melt the Arctic more). Such research has been conducted by scientists such as Dr. Jennifer Francis of Rutgers University and others, showing the jet stream slowing and becoming higher in amplitude since the 1960s. Such abrupt warming also leads events such as “sudden stratospheric warming” and “splitting” of the polar vortex, supporting Arctic blasts to the south and abundant heat transport to the Arctic.
If the ice sheet collapses completely (no more in summer, low to little meaningful extent in the polar night), you get even more abrupt warming of the sea surface from below and above through collapse of the ocean thermocline (persistently cold water “cap” atop somewhat warmer water) and air temperature inversion (warmer air atop cold surface air) as well as from the much reduced albedo (white, reflective surface). The warming atmospheric column with height further reduces the temperature gradient with the mid-latitudes, weakening the jet further and causing more extreme “wave action”, greater blocking patterns as you get these big waves and little eastward progression of systems and the polar jet actually retreats farther north. This can dramatically shift precipitation patterns northward could cause much hotter, drier conditions in the mid-latitudes. It’s been a major concern for a long time in in climate change science, but a process thought to be of concern in the “high emissions” scenarios of the mid to late 21st century as increasing aridity across the mid-latitudes would destroy forests and not allow crops to be grown where they are currently grown because of increasing extreme heat (or storms). So this would have impacts not only in the Arctic, but also in the mid-latitudes. Unfortunately, a recent phrase has been increasing use the past few years. “Faster than expected”. Some prominent researchers openly admit an ice-free Arctic may be possible before 2020. See also HERE.
I’ll have more on the situation in the Arctic this week as well as the heavy rainfall in the US. Also, keep an eye on Tropical Storm Gita approaching New Zealand to start the week!
–Meteorologist Nick Humphrey